These were reverted in gh-26530 (commit 17c4edc) due to refleaks.
* 2c1e258 - Compute deref offsets in compiler (gh-25152)
* b2bf2bc - Add new internal code objects fields: co_fastlocalnames and co_fastlocalkinds. (gh-26388)
This change fixes the refleaks.
https://bugs.python.org/issue43693
* Revert "bpo-43693: Compute deref offsets in compiler (gh-25152)"
This reverts commit b2bf2bc1ec.
* Revert "bpo-43693: Add new internal code objects fields: co_fastlocalnames and co_fastlocalkinds. (gh-26388)"
This reverts commit 2c1e2583fd.
These two commits are breaking the refleak buildbots.
A number of places in the code base (notably ceval.c and frameobject.c) rely on mapping variable names to indices in the frame "locals plus" array (AKA fast locals), and thus opargs. Currently the compiler indirectly encodes that information on the code object as the tuples co_varnames, co_cellvars, and co_freevars. At runtime the dependent code must calculate the proper mapping from those, which isn't ideal and impacts performance-sensitive sections. This is something we can easily address in the compiler instead.
This change addresses the situation by replacing internal use of co_varnames, etc. with a single combined tuple of names in locals-plus order, along with a minimal array mapping each to its kind (local vs. cell vs. free). These two new PyCodeObject fields, co_fastlocalnames and co_fastllocalkinds, are not exposed to Python code for now, but co_varnames, etc. are still available with the same values as before (though computed lazily).
Aside from the (mild) performance impact, there are a number of other benefits:
* there's now a clear, direct relationship between locals-plus and variables
* code that relies on the locals-plus-to-name mapping is simpler
* marshaled code objects are smaller and serialize/de-serialize faster
Also note that we can take this approach further by expanding the possible values in co_fastlocalkinds to include specific argument types (e.g. positional-only, kwargs). Doing so would allow further speed-ups in _PyEval_MakeFrameVector(), which is where args get unpacked into the locals-plus array. It would also allow us to shrink marshaled code objects even further.
https://bugs.python.org/issue43693
"Zero cost" exception handling.
* Uses a lookup table to determine how to handle exceptions.
* Removes SETUP_FINALLY and POP_TOP block instructions, eliminating (most of) the runtime overhead of try statements.
* Reduces the size of the frame object by about 60%.
* Add length parameter to PyLineTable_InitAddressRange and doen't use sentinel values at end of table. Makes the line number table more robust.
* Update PyCodeAddressRange to match PEP 626.
* Use instruction offset, rather than bytecode offset. Streamlines interpreter dispatch a bit, and removes most EXTENDED_ARGs for jumps.
* Change some uses of PyCode_Addr2Line to PyFrame_GetLineNumber
Added an invalidate_caches() method to the zipimport.zipimporter class based on the implementation of importlib.FileFinder.invalidate_caches(). This was done by adding a get_files() method and an _archive_mtime attribute to zipimport.zipimporter to check for updates or cache invalidation whenever the cache of files and toc entry information in the zipimporter is accessed.
* Mark bytecodes at end of try-except as artificial.
* Make sure that the CFG is consistent throughout optimiization.
* Extend line-number propagation logic so that implicit returns after 'try-except' or 'with' have the correct line numbers.
* Update importlib
zipimport's _unmarshal_code swallows import errors and then _get_module_code doesn't know the cause of the error, and returns the generic, and sometimes incorrect, 'could not find...'.
Automerge-Triggered-By: GH:brettcannon
* Provide native .files support on SourceFileLoader.
* Add native importlib.resources.files() support to zipimporter. Remove fallback support.
* make regen-all
* 📜🤖 Added by blurb_it.
* Move 'files' into the ResourceReader so it can carry the relevant module name context.
* Create 'importlib.readers' module and add FileReader to it.
* Add zip reader and rely on it for a TraversableResources object on zipimporter.
* Remove TraversableAdapter, no longer needed.
* Update blurb.
* Replace backslashes with forward slashes.
* Incorporate changes from importlib_metadata 2.0, finalizing the interface for extension via get_resource_reader.
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Break up COMPARE_OP into four logically distinct opcodes:
* COMPARE_OP for rich comparisons
* IS_OP for 'is' and 'is not' tests
* CONTAINS_OP for 'in' and 'is not' tests
* JUMP_IF_NOT_EXC_MATCH for checking exceptions in 'try-except' statements.
Remove BEGIN_FINALLY, END_FINALLY, CALL_FINALLY and POP_FINALLY bytecodes. Implement finally blocks by code duplication.
Reimplement frame.lineno setter using line numbers rather than bytecode offsets.
The peephole optimizer was not optimizing correctly bytecode after negative deltas were introduced. This is due to the fact that some special values (255) were being searched for in both instruction pointer delta and line number deltas.
This commit contains the implementation of PEP570: Python positional-only parameters.
* Update Grammar/Grammar with new typedarglist and varargslist
* Regenerate grammar files
* Update and regenerate AST related files
* Update code object
* Update marshal.c
* Update compiler and symtable
* Regenerate importlib files
* Update callable objects
* Implement positional-only args logic in ceval.c
* Regenerate frozen data
* Update standard library to account for positional-only args
* Add test file for positional-only args
* Update other test files to account for positional-only args
* Add News entry
* Update inspect module and related tests
The lineno and col_offset attributes of AST nodes for list comprehensions,
generator expressions and tuples are now point to the opening parenthesis or
square brace. For tuples without parenthesis they point to the position
of the first item.
There are some same consts in a module. This commit merges them into
single instance. It reduces number of objects in memory after loading modules.
https://bugs.python.org/issue34100
Current support for hash-based bytecode files in `zipimport` is rather
sparse, which leads to test failures when the test suite is ran with
the ``SOURCE_DATE_EPOCH`` environment variable set.
This teaches zipimport to handle hash-based pycs properly.
Guido van Rossum
Eric Snow
Pablo Galindo
Ken Jin
Mark Shannon
Inada Naoki
Brett Cannon
Desmond Cheong
Irit Katriel
Jason R. Coombs
Serhiy Storchaka
Xtreak
Zackery Spytz
Steve Dower
Anthony Sottile
INADA Naoki
Elvis Pranskevichus